Medical devices having elongated body portions can be introduced through a body opening or tract and manipulated to move material (e.g., blood clots, tissue, biological concretions, medical device components) within the body. Using such devices positioned at a treatment site through an elongated endoscope, laparoscope, or ureteroscope, an operator can view and operate simultaneously at a remote surgical site. Lithotripsy and ureteroscopy, for example, are used to treat urinary calculi (e.g., kidney stones) in the ureter of a patient. In ureteroscopy, an operator inserts a medical retrieval device such as a surgical grasper or a metal wire basket into the urinary tract to capture a stone in the retrieval assembly. Holding the stone in position within the retrieval assembly, the operator fragments it using a laser fiber. The operator can then remove the fragments by the same or a different medical retrieval device or leave them in the body to be eliminated naturally.
Medical retrieval devices can include a sheath and an object-engaging unit, such as a basket, that is moveable relative to the sheath from a collapsed state within the sheath to another state in which the unit extends past the distal end of the sheath. The sheath typically extends from a handle, located at the proximal end (i.e., the end away from the patient) of the sheath to the object-engaging unit which is located at the distal end of the sheath (i.e., the end near the patient and that goes into the patient). The handle includes a mechanism for actuating the object-engaging unit in order to move the object-engaging unit between collapsed and extended, expanded states.
During a urological procedure, a physician should be able to move the distal end of the medical retrieval device in relation to the distal end of a ureteroscope. The physician may grip the sheath just proximal to the point where the sheath is introduced into an auxiliary channel within the ureteroscope. As the physician operates the ureteroscope and positions the sheath of the retrieval device, an assistant actuates the handle at the physician's direction to retrieve or manipulate foreign material.
In procedures that utilize a laser fiber and retrieval device, the physician must carefully hold and position both items relative to each other as well as relative to the ureteroscope. Actuation of the devices with the assistance of another operator can be overly time consuming, cumbersome, and lacking in tactile sensitivity. Currently, operators use at least two hands to manipulate urinary calculi and fragments thereof. To retain the object(s) or hold the retrieval device in a certain position and location, the operator should maintain constant tension on the handle. To rotate or move the device, the operator should maintain that tension while rotating the handle, often requiring another operator. There exists a need for a locking mechanism that allows a physician to release tension on the handle without changing the tension of the device on the captured object. Currently, physicians who need to maintain a certain position of the basket in the process of manipulating a stone must employ an attending assistant to actuate the device, which adds cost and separates the physician from the tactile feel of the device.
Retrieval of fragments of urinary calculi within the body can be problematic in that stones or stone fragments in the ureter often migrate within the body before, during, and after a lithotripsy procedure. Therefore, a need exists in the art for a retrieval device that facilitates the initial capture of material as well as maintaining its capture during further positioning and removal of the material and device. In addition, there exists a need in the art for a retrieval device that facilitates the controlled release of a stone or fragment during a surgical procedure. For example repositioning a target stone relative to a lithotripter or releasing captured stones to large to release without fragmentation requires controlled release of material.
Operators of medical retrieval devices need an improved handle that allows for the introduction, positioning, and actuation of the device with a single hand. An improved handle would allow an operator to simultaneously position and manipulate two devices relative to each other. Additionally, using an improved handle, an operator could simultaneously manipulate an endoscope or an additional medical device without assistance. Improved configurations for those devices should exhibit improved capabilities for sustained capture, controlled release, and limited patient tissue trauma while allowing operation of the devices without the need for two hands or an assistant. There is also a need for smaller handles that have more ability to manipulate objects so that the primary operator has the highest possible tactile sensation of and control over the object to be captured or manipulated.